#define F_CPU 1000000UL
#include<avr/io.h>
#include <avr/interrupt.h>
#include <string.h>
#include <stdio.h>
#include <math.h>
#include <util/delay.h>
// 5 digit 7 segment display, common anode, connected to the PB0-PB7
// Interrupt on change signals connected to the PD2-PD3
// A button is pulled up, connected to PD0
// PNP transistors as the emitter keys for the common anodes of the digits, connected to the PC0-PC4

volatile float N = 0;
volatile uint8_t ibutt = 0;

void PrintNum(float N) // Head 5 digit 7-seg function, 2 decimal precision, common anode
{
 int32_t n = round(N*100);
 if (n<0){n *= -1;}  
 while (n>99999){n = n-100000;}
 uint8_t numd[5] = {0,0,0,0,0};
 numd[0]=n/10000;
 numd[1]=n%10000/1000;
 numd[2]=n%1000/100;
 numd[3]=n%100/10;
 numd[4]=n%10;

 uint8_t digit[5] = {0b11111110, 0b11111101, 0b11111011, 0b11110111, 0b11101111}; //Digit mask
 
 const uint8_t dmask[10] = {0xC0, 0xF9, 0xA4, 0xB0, 0x99, 0x92, 0x82, 0xF8, 0x80, 0x90}; //digits 0-9, "0 = led on".

 PORTB = dmask[numd[0]];
 if(numd[0] == 0){PORTB = 0xFF;}
 if(N<0){PORTB &= 0xBF;}
 PORTC = digit[0];
 _delay_us(250);

 if(numd[0] == 0 && numd[1] == 0){PORTB = 0xFF;}
 else{PORTB = dmask[numd[1]];}
 PORTC = digit[1];
 _delay_us(250);

 PORTB = dmask[numd[2]];
 PORTB &= 0b01111111;
 PORTC = digit[2];
 _delay_us(250);

 PORTB = dmask[numd[3]];
 PORTC = digit[3];
 _delay_us(250);

 PORTB = dmask[numd[4]];
 PORTC = digit[4];
 _delay_us(250);

 PORTC = 0xFF;
}

void buttoncheck(void)
{				
  if(!(PIND&0x01))
  {
   if (ibutt < 3)
   {ibutt++;}
   else
   {
     N = 0; // Do something if button pressed
     ibutt = 0;
   }
  }
  else
  {ibutt = 0;}
}


ISR(INT0_vect)  //
{
  if(PIND&0x04)  //PD2 is up
  {
    if(PIND&0x08)  //PD3 is also up
    {N += 0.0423333333333;}
    else
    {N -= 0.0423333333333;}
  }
  else
  {
    if(PIND&0x08)  //PD3 is up
    {N -= 0.0423333333333;}
    else
    {N += 0.0423333333333;}
  }
}


ISR(INT1_vect)  //
{
  if(PIND&0x08)  //PD2 is up
  {
    if(PIND&0x04)  //PD3 is also up
    {N -= 0.0423333333333;}
    else
    {N += 0.0423333333333;}
  }
  else
  {
    if(PIND&0x04)  //PD3 is up
    {N += 0.0423333333333;}
    else
    {N -= 0.0423333333333;}
  }
}




main()
{
  DDRB = 0xFF; 		// output port  
  DDRC = 0xFF; 		// output port  
  DDRD = 0x00; 		// input port
  PORTB = 0xFF;	
  PORTC = 0x00;	
  PORTD = 0x0D;		// pull-up resistors on PD0, PD2, PD3

  GICR |= (1<<INT0);	// allowing an external interrupt for INT0
  GICR |= (1<<INT1);	// allowing an external interrupt for INT1
  MCUCR |= (1<<ISC00);  // logical change interrupt
  MCUCR |= (1<<ISC10);  // logical change interrupt

  sei();
  PORTB = 0b00000000; 
  PORTC = 0b11100000;
  _delay_ms(250);
  PORTB = 0xFF; 
  PORTC = 0xFF;
  while(1)
  {
  buttoncheck();
  PrintNum(N);
  }
}